Affiliations: [a] Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| [b] Department of Geriatric Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| [c] Division of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| [d] Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA
Correspondence:
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Correspondence to: Kevin Biju, MS, Johns Hopkins Department of Otolaryngology-Head and Neck Surgery, 601 N. Caroline Street, Baltimore, MD 21287, USA. Tel.: +484 624 2992; E-mail: kbiju1@jhmi.edu.
Abstract: Background:Patients with Alzheimer’s disease (AD) are at high risk for falls. Vestibular dysfunction predicts balance impairment in healthy adults; however, its contribution to falls in patients with AD is not well known. Objective:The objective of this study was to assess whether vestibular function contributes to balance and fall risk in patients with AD. Methods:In this prospective observational study, we assessed vestibular function using measures of semicircular canal (vestibulo-ocular reflex (VOR) gain) and saccular function (cervical vestibular-evoked myogenic (cVEMP) response), and we assessed balance function using the Berg Balance Scale and quantitative posturography. We evaluated falls incidence for a mean 1-year follow-up period (range 3–21 months) in 48 patients with mild-moderate AD. Results:Relative to matched controls, AD patients exhibited increased medio-lateral (ML) sway in eyes-open (0.89 cm versus 0.69 cm; p = 0.033) and eyes-closed (0.86 cm versus 0.65 cm; p = 0.042) conditions. Among AD patients, better semicircular canal function was associated with lower ML sway and antero-posterior (AP) sway in the eyes-closed condition (β= –2.42, 95% CI (–3.89, –0.95), p = 0.002; β= –2.38, 95% CI (–4.43, –0.32), p = 0.025, respectively). Additionally, better saccular function was associated with lower sway velocity (β= –0.18, 95% CI (–0.28, –0.08); p = 0.001). Finally, we observed that better semicircular canal function was significantly associated with lower likelihood of falls when adjusted for age, sex, and MMSE score (HR = 0.65; p = 0.009). Conclusion:These results support the vestibular system as an important contributor to balance and fall risk in AD patients and suggest a role for vestibular therapy.
Keywords: Alzheimer’s disease, cognitive aging, falls, postural balance, vestibular function tests
